Siemens, Deutsche Post, BASF, Bayer and Samsung Electronics are the top five global leaders in a new 2010 Global 500 report and leadership index released by the Carbon Disclosure Project (CDP). These companies are in the CDP Carbon Performance Leadership Index (CPLI) and scored highest — 95 or above out of 100 — in the Carbon Disclosure Leadership Index (CDLI).

The Carbon Disclosure Project asks 500 global companies annually on behalf of 534 institutional investors representing more than $64 trillion of asset, to measure and report their emissions as well to assess how climate change will impact their future financial performance, reports Reuters.

Only 18 percent or 90 companies of the Global 500 did not respond to the 2010 CDP request. These include eight in China, 12 in Hong Kong, 3 in Poland, eight in Russia and four in Singapore.

The report, produced by PwC and sponsored by Bank of America Merrill Lynch, finds that carbon management is becoming a strategic business priority and competitive driver for the largest global companies, despite the lack of a global climate change agreement.

World leaders could not agree on a binding agreement at the Copenhagen climate change meeting last December. However, they will try again at the climate change summit set for November in Cancun, Mexico.

A key finding reveals that 85 percent of these global companies reported having board or senior executive level responsibility for climate change and nearly half (48 percent) are now embedding climate change initiatives into the overall business strategy and across the organization.

The report also finds that nine out of ten companies identified significant commercial opportunity from climate change.

However, only 19 percent of the Global 500 companies show significant emissions reductions despite 65 percent of them implementing emissions reduction targets. According to the report, although global emissions fell one percent last year, Scope 1 emissions reported by the Global 500 rose to 3.4 billion metric tonnes CO2-e, which now accounts for 11 percent of total global emissions.

The report also reveals that North American companies lag behind European firms in terms of disclosure and performance. Only six percent of North American respondents are in the CPLI compared to 21 percent of European companies.

A key reason could be that the European Union has put mandatory caps on greenhouse gas emissions from large sources since 2005, while the United States, the world’s second biggest greenhouse gas polluter after China, has no federal limits on emissions, reports Reuters. However, the U.S. has pledged to cut emissions 17 percent by 2020 despite a lack of support for climate change legislation by the Senate.

The global report shows that companies are focused on two main areas: energy efficiency of operations, driven by cost savings, and the development of innovative products and services that enable customers to cut their emissions, says CDP.

The Global 500 Report was launched today at the CDP Global Forum, which marks the beginning of Climate Week.